A4 2000- If you can find a (reputable) Autopian in your area, they'll be able to get you up to speed quickly.
Otherise, the trick to using a buffer like yours is to work with products that are what I call "Accumulator-proof" :chuckle:
As craigdt suggested, using something that might not break down correctly can cause problems. SO...I'd choose products that aren't prone to those kinds of issues.
Something that works OK by hand should work OK with most any machine because the machine will basically just be a "mechanical hand that moves sorta slowly but doesn't get tired". Back to my Meguiar's product suggestions....
And as noted, if the cost isn't prohibitive, a really good polisher can be a godsend. Judging from your user-name, you're an Audi fan, and I can tell you straight out that to keep Audis looking (really) nice you simply need a good polisher that can work with hard clearcoats. (Not that you'll be taking off paint all the time

) Consider that I got my then-octogenarian father up to speed with a polisher (on his Audi) in about 15 minutes, no exaggeration. Yeah, doing some of the miracle-corrections you see here takes a bit of experience, but just speeding things up while doing no harm is something you'll find easily mastered.